So I was out a friends house today... He asked me when I left his house the last time if I hit my horns when I got back into town. I thought about it for a second and remembered seeing a buddy just as I got into town and honked at him. My friend said I left, and about 10 mins later he was out in his front yard and he heard me honk! After I got home I googled his house and the location I was at when I saw my buddy in town and honked... 4.3 miles!!!

I really didn't think this was possible, but he described exactly how I honked... short chirp, short chirp, long chirp...

 

The nearest crossing to my house is 4.8 miles and I can hear the locomotives blowing their horns when it's quiet out, usually in the evenings.

- NCSU

 

Locomotive air horns typically operate at 110psi-120psi, as that is their Main Res pressure and they're obviously plenty loud. I should know, I work on 'em! Don't go much over 160, as you run the risk of blowing out the diaphragms. Nathan Airchime tests them at the factory around 160, I believe. The details are on their website.

 

My tank is 200 psi, but I'm not really sure what pressure is actually getting to my K5LA. It's loud though.

 

Which compressor do you have? Is it a separate unit from the tank? How quickly does it recharge?

 

I have the Viair dual 480c setup that fills a 20-gallon tank. It takes a whie to fill, but it hardly ever runs. With 20 gallons at 200 psi, it takes several long blasts before the compressors kick on.